How your Synergy bill changes after solar in Perth

Your Synergy bill after solar installation looks quite different from what you received before. Most Perth solar owners don't fully understand the new format — which makes it hard to spot errors.

Here's what each section means and how to check that your bill is correct.

What changes on your bill

Before solar, your bill showed:

• A supply charge (fixed daily amount)
• Usage charges (kWh consumed × tariff rate)
• Total amount payable

After solar, your bill adds:

• Import metering (electricity you drew from the grid)
• Export metering (electricity you sent to the grid)
• DEBS credits (payment for your exported electricity)
• A net total that subtracts export credits from import charges

Understanding the meter readings

With solar, your smart meter records two different flows:

Import (consumption from grid): The electricity you drew from Synergy's network when your solar wasn't generating enough for your needs. Typically occurs early morning, evening, and overnight.

Export (generation to grid): The surplus solar electricity you sent back to the network. Recorded in kWh during daylight hours when your panels generated more than your household used at that moment.

Your bill should show both meter readings: the opening reading, the closing reading, and the difference (kWh for the billing period).

Checking meter reads: If your bill shows an estimated read (marked 'E' on the meter type column), it means the meter wasn't read and Synergy estimated your consumption. Estimated reads on a solar account can be inaccurate because they don't account for your actual generation. If you have a smart meter (and solar connection requires one), estimates should be rare — they usually indicate a communication issue between the meter and Synergy.

The DEBS credit line

The Distributed Energy Buyback Scheme (DEBS) credit appears as a negative amount on your bill — a credit that reduces what you owe.

How it's calculated:

Under DEBS, your export is paid at different rates depending on time of day:

• Peak hours (3pm–9pm): 10c/kWh
• Off-peak hours (all other times): 2c/kWh

Your meter records export in 30-minute intervals (on a smart meter). The DEBS credit on your bill reflects the total export across the billing period, separated into peak and off-peak volumes, and credited at the respective rates.

What the credit line looks like: Something like:

• DEBS Off-Peak Export: 450 kWh × $0.02 = −$9.00
• DEBS Peak Export: 35 kWh × $0.10 = −$3.50
• Total DEBS Credit: −$12.50

Checking the credit: Compare the export kWh on your bill to your inverter's monitoring data for the same period. They should be close (within a few percent — the meter and inverter may measure slightly differently). A large discrepancy (e.g., your inverter shows 600 kWh exported but the bill shows 400 kWh) warrants a call to Synergy.

Why your bill might still be higher than expected

Reason 1 — You're not yet on Midday Saver

If you installed solar and expected to benefit from Midday Saver's super off-peak rate (8.85c/kWh, 9am–3pm), but you're still on A1, you're paying 33.26c/kWh for all imports. To switch to Midday Saver, you need to contact Synergy after installation — it doesn't happen automatically.

Reason 2 — High evening consumption

Solar generates during the day; most household consumption happens in the morning and evening. If your household has high evening load (ducted AC running 3pm–10pm, multiple TVs, EV charging overnight), you're importing significant grid electricity when solar isn't generating.

Reason 3 — Winter billing period

A winter quarter bill will show less DEBS credit and more import than a summer bill, because days are shorter and lower sun angles reduce generation. Perth's June–August generation can be 40–50% of December–January peak. Your first winter bill after solar may be higher than your pre-solar winter bill if your consumption habits haven't changed.

Reason 4 — System not operating at full capacity

If your inverter had a fault for part of the billing period (a common inverter error that was never noticed), generation would be lower than expected. Cross-check your inverter monitoring data: what did the system actually generate this billing period?

Checking your bill is correct

Go through this checklist when your first few post-solar bills arrive:

1. Are both import and export meter readings present? If only one set of readings appears, your account may not have been updated to a solar-capable billing arrangement. Contact Synergy.

2. Is the tariff correct? Your bill header should show your tariff type (A1, Midday Saver, EV Add-On, etc.). Verify it matches what you expected.

3. Does the export volume match your monitoring? Open your inverter app (iSolarCloud, SolarWeb, Enlighten, etc.) and check the export figure for the billing period. Compare to the bill.

4. Are DEBS peak and off-peak rates applied correctly? Peak rate is 10c/kWh (3pm–9pm); off-peak is 2c/kWh (all other times). If you're on Midday Saver, the rates and timing bands are the same under DEBS — only import rates differ by tariff, not DEBS export rates.

5. Is the supply charge correct? A1 supply charge: 119.24c/day. Midday Saver supply charge: same. If the supply charge looks unusually high, the number of days in the billing period may be longer than usual.

How much should your bill be?

A family home in Perth with a 6.6kW solar system, on Midday Saver, with moderate evening consumption might see:

• Quarterly supply charge: ~$109 (90 days × $1.19/day)
• Import charges: $150–$250 (evening/overnight/winter imports)
• DEBS credits: −$15–$40 (quarterly export at 2c/10c)
• Net quarterly bill: $220–$320 (down from $500–$700 before solar)

This is an estimate — your actual bill depends on your consumption profile, system size, and season.

The first bill after installation will cover only part of the quarter (from installation date to billing period end). A partial-period bill looks unusual — that's expected.

Tariff rates, DEBS rates, and supply charges reflect Synergy A1 and Midday Saver tariffs effective 1 July 2026. If your bill reflects pre-July rates (before your billing period started after 1 July), rates from the previous financial year may apply for part of the period.